Device for rounding filament ends for a toothbrush head

ABSTRACT

The invention relates to a device ( 1 ) for rounding the filaments of a toothbrush head, comprising a rounding tool ( 2 ) and a means ( 3 ) for guiding the tool ( 2 ) on a path of movement that finishes the filaments. The invention provides that the guiding means is configured as a linear guide ( 3 ) by means of which the tool ( 2 ) can be linearly displaced relative to at least two axes ( 5, 6 ).

The present invention relates to a device for rounding filament ends for a toothbrush head, having a rounding tool and having means for guiding the tool on a path of movement that processes the filaments.

PRIOR ART

Such a device is known from EP 1 395 144 A1. This device has a tool fashioned as a rotatable sanding wheel that describes an elliptical movement path as an advance during the processing of the filaments. For this purpose, the sanding wheel is connected eccentrically to a planet gear of a planetary gear system that meshes with the inner toothing of a ring gear of the planetary gear system.

In the known rounding device, the eccentric mounting of the sanding wheel causes an imbalance that has to be compensated by corresponding countermeasures in order to avoid damage to the device. For this purpose, an additional planet gear is provided situated on the side opposite the planet gear driving the sanding wheel, and also engaging with the inner threading of the ring gear of the planetary gear system. Due to such necessary compensating measures, the known rounding device can be realized only with a high technical outlay, and is therefore relatively expensive. In addition, due to its construction, the known rounding device is limited to only the elliptical advance movement path of the tool, and is therefore not suited to moving the tool along other movement paths.

OBJECT OF THE INVENTION

Based on this background, the present invention has the object of providing a device for rounding filaments for a toothbrush head having the features named above, in which the tool can be moved flexibly along almost any movement path, and which is at the same time technically easy to realize.

INVENTION AND ADVANTAGEOUS EFFECTS

In order to achieve this object, a rounding device is proposed having the features named in claim 1. The rounding device is distinguished in that, inter alia, the guide mechanism is fashioned as a linear guide by means of which the tool can be linearly displaced relative to at least two axes.

Through this measure, the tool can be moved along almost any movement path, by displacing the tool as needed relative to the respective axis. Thus, the rounding device is no longer limited solely to an elliptical movement path of the tool, as is the case in the known device. The compensating elements also provided in the known device can be omitted in the device according to the present invention. Because of this, the device according to the present invention is structurally easy to realize. The device according to the present invention is equally applicable to toothbrush filaments already set in the toothbrush head, or that are to be pre-treated independent of the head, and that are in the form of filament bundles or filament strands, unwound from filament spools, etc.

According to a first embodiment of the invention, the linear guide is formed by at least two, preferably separate, guides. In this way, the linear guide can easily be manufactured, for example from two guides of identical construction. Simple installation of the linear guide is also achieved by its multipart construction. Preferably, each of the at least two axes should be attached respectively to one of the guides, so that the tool is displaced in a guided fashion both along the one axis and along the other axis using an easily constructed linear guide.

According to another embodiment of the invention, the guides are capable of being moved relative to one another. In this way, the tool can be displaced in guided fashion along desired movement paths in a particularly flexible manner. This achieves a high degree of variability in the rounding of the filaments.

According to another embodiment of the invention, at least one of the guides is situated so as to be stationary, and the other guide is capable of being displaced relative thereto. This enables a simple positional determination of the tool, because the stationary situation of one of the guides establishes an unchangeable reference system. This facilitates detection of the position of the tool, for example using an electronic detection system.

Here it is recommended that the tool, or a receptacle for the tool, be capable of being fixed to the movable guide. In this way, the device as a whole can be compactly constructed, despite its flexibility.

It is also recommended that the guides be capable of being oriented to one another in such a way that the axes lie at a prespecified angle to one another. This measure is intended to enable flexible setting of the advance movement of the tool to a desired movement path.

Here it is advantageous that the guides be situated or oriented to one another in such a way that the axes are at a right angle to one another. With this orientation of the guides, the overall device can easily be realized technically. In addition, a particularly large range of movement of the tool can be realized in which the tool can be displaced in guided fashion.

According to another embodiment of the invention, the guides are coupled with one another via a moving part that is preferably capable of being displaced on one of the guides and on which the other guide is mounted so as to be capable of displacement. In this way, the tool can be moved along the one axis via one of the guides, and can be moved independently thereof along the other axis, the tool executing in each case a guided advance movement by means of the linear guide.

In this way, the moving part can be fashioned as a cross slide or pivot slide, depending on whether the angle between the two guides is to be fixed or adjustable. In the present context, a “cross slide” is understood to be a moving part in which the guides are fixedly held at a right angle to one another. In contrast, a “pivot slide” is understood to be a moving part in which the guides are situated at an adjustable angle to one another.

Advantageously, the guides have lateral limit stops to limit the guided displacement path and to prevent the guided components from moving apart outside of the guides.

According to another idea of the present invention, at least two drives are provided for the linear displacement of the tool. This measure results in a high degree of flexibility for the drive possibilities for the tool. For example, the tool can be displaced along the two axes simultaneously, the movements along these axes being realizable separately from each other because of the two drives.

Here it is recommended that the drives be fashioned as rotary drives effectively connected to the tool via a coupling gear mechanism. In this way, the tool can be driven in a technically simple manner because on the one hand inexpensive motors can be used, and an advance movement of the tool can easily be achieved in all the positions that can be obtained using the guides.

It is advantageous if the rotational speed of the drives can be regulated, and/or the rotational direction of the drives can be reversed. This achieves a high degree of flexibility for the drive movement for the tool.

According to an advantageous embodiment of the invention, the drives are effectively connected to one another via the coupling gear mechanism in such a way that when the drives are rotating in the same direction, the tool is displaced relative to one of the axes, and when the rotational directions are opposite, the tool is displaced relative to the other axis. In this way, the displacement of the tool relative to one of the axes is possible in a technically simple manner, because all that is required to achieve this are drives having reversible rotational directions. Alternatively, the cross slide and/or pivot slide is driven via direct drives using linear motors.

For a similar purpose, the coupling gear mechanism is fashioned as a traction gear mechanism, preferably a belt gear mechanism. Such mechanisms are easier to realize from the point of view of manufacturing technology and are thus significantly less expensive than wheel gear mechanisms, for example. In addition, traction mechanisms enable transmission of the rotational movements even over greater distances.

According to another embodiment of the invention, the deflection mechanism of the traction mechanism is situated on the guides and on the moving part. In this way, a coupling of the guides and the moving part to the traction mechanism is achieved, in order to enable execution of a movement of the tool along the axes.

Preferably, the traction mechanism should be under pre-tension in order to ensure a high degree of operational safety and to prevent the traction mechanism from springing out of the deflection mechanism during operation of the device.

It is advantageous if the deflecting mechanisms are arranged with axes parallel to one another, and the traction mechanism is guided in a plane, preferably by means of the deflection mechanism. In this way, deflecting mechanisms that are easy to manufacture, such as rollers, can be used. In addition, a lateral displacement of the traction mechanism over its guided length is avoided, and thus the danger of the traction mechanism jumping out of the deflecting mechanism during operation of the device is avoided.

According to an advantageous embodiment of the invention, the deflecting mechanisms attached to the guides are situated at opposite ends of the guides. In this way, the components of the device to be guided are not mutually hindered by the traction mechanism during operation of the device. Preferably, the deflection mechanism should be situated on the lateral limit stops of the guides in order to enable full use of the displacement path created by the guides.

In another embodiment of the invention, the deflection mechanisms attached to the stationary guide are each capable of being driven by one of the drives. In this way, the tool can be displaced relative to one or the other axis as a function of the rotational direction of the two drives, if the guides are coupled to one another via a moving part and deflection mechanisms for the traction mechanism are situated on the ends of the guides and on the moving part.

It is provided that the traction mechanism has two ends and that a deflection mechanism attached to the movable guide is fashioned for fixing the ends. In this way, it is easily possible to construct the traction mechanism so that no components are situated in the area of the tool that would impair the accessibility of the tool, because the ends of the traction mechanism are fixed there. Because of this, it is recommended that the ends of the traction mechanism be attachable to one of the lateral limit stops of the movable guide, in particular to the limit stop connected to the tool.

Alternatively, it can of course also be provided that the traction mechanism be fashioned so as to be circulating, i.e. without a beginning and end. In this way, during operation of the gear mechanism the traction mechanism is moved in a circulating fashion. The circulating construction of the traction mechanism is advantageous in particular if the two drives have different rotational speeds, because this does not impair the traction mechanism from transmitting movement, but rather simply is noticeable in the form of slippage at the deflection mechanism. Because of this, changing the rotational direction of the circulating traction mechanism can also be relatively slow, and if differences in the rotational speeds between the drives occur, this does not impair the function of the gear mechanism. In contrast, given a gear mechanism having the traction mechanism fixed at the ends, it is necessary to switch rotational directions of the drives rapidly to avoid differences in rotational speeds between the drives when the rotational direction is reversed. In such a traction mechanism, this would result in overextension in one strand and loosening of the traction mechanism in another strand of the traction mechanism, thus causing the traction mechanism to slide out of the deflecting mechanism.

According to another basic idea of the invention, at least one device is provided for controlling and/or regulating at least the rotational direction and, if warranted, the rotational speed of the drives to specifiable parameters in order to describe a specified movement path of the tool. In this way, the tool can easily describe, in fully automated fashion, highly precise complex prespecified paths in its advance movement. This is very convenient for the operator of the device.

It is recommended that the control/regulation device control or regulate the rotational direction and, if warranted, the rotational speed of the drives in such a way that the movement path of the tool describes a circular, elliptical, figure-eight, or cardioid path. Back-and-forth movements at an angle to each other are also possible. In this way, the tool can be displaced along the standard movement paths for rounding the toothbrush filaments without requiring switching times for changing from one movement path to another movement path. This ensures a high degree of flexibility of the advance movement of the tool.

According to another idea of the invention, the tool is arranged to execute a principal movement for the processing of the filaments of the toothbrush head. This achieves a particularly effective processing of the filaments in that the tool executes an advance movement lying on a prespecified movement path, and additionally executes a principal movement for processing the filaments. Preferably, this principal movement should be a rotational movement so that the filaments can be processed by means of one or more rotating sanding wheels, for example.

It is also advantageous that the rotational speed and rotational direction of the tool be controllable, and that it be independent of the linear movement axes with respect to rotational speed and rotational direction of the drive. This ensures a particularly high degree of flexibility in the processing of the filaments.

According to another idea of the invention, a feeding-in unit is provided to move the tool into the processing position. In this way, the tool can be moved from its processing position into a maintenance position, for maintenance, for example. After maintenance of the tool is complete, the tool can advance into the processing position without operator effort. In addition, the feed-in unit is used to control the process parameters, e.g. the pressure or force with which the filament ends press against the sanding wheel, or in order to control the advance path and the advance speed.

The rounding device is preferably used in plugging machines or in spool-feeding machines for manufacturing a toothbrush or the bristles thereof. The rounding device is also suitable for use in machines for manufacturing prototypes for toothbrushes and for rounding pre-cut filaments in, for example, filament bundles or hanks, or of filament spools or filament pucks.

ILLUSTRATIVE EMBODIMENTS

Additional goals, advantages, features, and possible uses of the present invention result from the following description of two illustrative embodiments, based on the drawings. All described and/or graphically represented features, alone or in arbitrary combination, form the subject matter of the present invention, independent of their summarization in the claims or the dependencies therein.

FIG. 1 shows a possible illustrative embodiment of a device for rounding filaments of a toothbrush head, in a top view, and

FIG. 2 shows another possible illustrative embodiment of the rounding device in a top view.

FIG. 1 schematically shows a device 1 for rounding filaments of a toothbrush head, the toothbrush and toothbrush head not being shown. Such a rounding device 1 can, for example, be used as a separate system, as an individual machine for rounding filament ends without being directly incorporated into a toothbrush manufacturing machine, or can be integrated into a plugging or spool-feeding machine, or into some other toothbrush manufacturing machine.

For the processing of the filaments, device 1 has a tool 2 that can be fashioned for example as a sanding wheel. Tool 2 can itself execute a principal movement for processing the filaments, such as a rotational movement.

The device further has mechanism 3 for guiding tool 2 on a movement path that processes the filaments. This movement path can correspond to the advance movement path of tool 3. This movement of tool 2 can also actually be the principal movement which carries out the rounding of the filaments.

It is provided that the guide mechanisms be fashioned as linear guide 3 by means of which tool 2 can be displaced linearly relative to at least two axes 5, 6. In this way, the movement path of the tool can be made variable by moving the tool linearly in any way along the axes so that it is not restricted to only one movement path.

Linear guide 3 can be formed by at least two separate guides 7, 8, allocated respectively to at least the two axes 5, 6. A high degree of flexibility for the determination of the movement path for tool 2 is possible if guides 7, 8 can be moved relative to one another.

Here, at least one of the guides 7, 8 can be stationary, and the other guide 8 can be moved relative to it. In the illustrative embodiment according to FIG. 1, tool 2 is fixed to the other, movable guide 8, preferably via a retainer 14.

Guides 7, 8 are oriented to one another in such a way that the axes 5, 6 are at a right angle to one another. In addition, guides 7, 8 are coupled to one another via a moving part 9 that is fashioned in the manner of a cross slide. Moving part 9 is situated on one of the guides 7, 8 so as to be linearly displaceable. In addition, the other guide 8 is held on moving part 9 so as to be linearly displaceable.

In order to limit the movement of cross slide 9 in guide 7, or the movement of guide 8 on cross slide 9, guides 7, 8 have lateral limit stops 10, 11, 12, 13.

The illustrative embodiment of rounding device 1 according to FIG. 1 is constructed in such way that when device 1 is assembled, linear guide 3 is fashioned so as to displace tool 2 in the horizontal and vertical direction.

In addition, device 1 has at least two drives 15, 16 for the linear displacement of tool 2. The drives are fashioned as rotary drives 15, 16 that are effectively connected to tool 2 via a coupling gear mechanism 17.

Coupling gear mechanism 17 is fashioned in the manner of a traction mechanism, such as a belt mechanism. Alternatively, the cross slide and/or pivot slide are driven via linear-motor direct drives.

Drives 15, 16 are both controllable in their rotational speed, and/or are reversible in their rotational direction. In order to enable flexible displacement of tool 2 along axes 5, 6, drives 15, 16 are effectively connected to one another via coupling gear mechanism 17 so that when drives 15, 16 are rotating in the same direction, tool 2 is displaced relative to one of the axes 5, 6, and when the directions of rotation are not the same, tool 2 is displaced relative to the other axis 6.

In this connection, in the illustrative embodiment according to FIG. 1 deflection mechanisms 18, 19, 20, 21, 22 are situated as rotatable rollers of traction gear mechanism 17, on guides 7, 8 and on moving part 9, via which traction mechanism 24 of traction gear mechanism 17 is deflected. Traction mechanism 24 is preferably subject to a pre-tension.

Deflecting mechanisms 18, 19, 20, 21, 22 are situated with axes parallel to one another, and preferably guide traction mechanism 24 essentially in one plane. Deflection mechanisms 18, 19, 20, 21 attached to guides 7, 8 are preferably situated at the opposite ends of guides 7, 8, preferably on the lateral limit stops 10, 11, 12, 13 of guides 7, 8.

Of deflecting mechanisms 18, 19, 20, 21, 22, the deflecting mechanisms 18, 19 attached to stationary guide 7 are each capable of being driven by one of drives 15, 16.

In the illustrative embodiment according to FIG. 1, traction mechanism 24 driven by drives 15, 16 is what is known as an open traction mechanism, having two ends 25, 26 fixed to movable guide 8, preferably to the lateral limit stop 14 thereof. Preferably, the lateral limit stop 13 used here is part of receptacle 14 for tool 2. For this reason, deflecting mechanism 21 is fashioned for fixing the ends 25, 26 of traction mechanism 24.

In addition, rounding device 1 has at least one device 27 for controlling and/or regulating at least the rotational direction and, if warranted, the rotational speed of drives 15, 16 as a function of specifiable parameters, for describing a specified movement path of tool 2. For this purpose, control/regulation device 27 controls or regulates the rotational direction and, if warranted, the rotational speed of drives 8, 9 in such a way that the movement path of tool 2 describes a circular, elliptical, figure-eight, or cardioid path. Of course, control/regulation device 27 can also be used to displace tool 2 along movement paths other than those listed above. In principle, using the control and/or regulation device, a simple back-and-forth movement of tool 2 or of the rotational speed of the sanding wheel and/or of the advance movement is possible.

In addition, an advance unit 28 can move tool 2 into the processing position, and can bring it into a maintenance position, for example, from the processing position, or can control the process parameters.

FIG. 2 shows a schematic representation of another illustrative embodiment of rounding device 1. Components of this illustrative embodiment that are the same as the components of the illustrative embodiment shown in FIG. 1 have the same reference indicators; regarding these, reference is made to the description of the illustrative embodiment according to FIG. 1.

The illustrative embodiment of rounding device 1 according to FIG. 2 differs from the illustrative embodiment according to FIG. 1 in that, inter alia, a circulating traction mechanism 23 is provided. Because of this, traction mechanism 23 circulates during operation of the device, and is not fixedly connected to a lateral limit stop 13 of movable guide 8, as in the illustrative embodiment according to FIG. 1.

Deflecting mechanisms 18, 19, 20, 21, 22 are preferably fashioned as rotatable rollers.

The functioning of rounding device 1 can be described as follows:

When drives 15, 16 rotate in the same direction, and preferably at the same rotational speed, tool 2 is displaced along axis 5. Depending on the rotational direction of drives 15, 16, tool 2 is moved in one or the other direction along axis 5.

When drives 15, 16 have rotational directions opposed to one another, and preferably have the same rotational speed, tool 2 moves along axis 6. Depending on the directions in which drives 15, 16 rotate opposite to each other, tool 2 is moved in one or in the other direction along axis 6.

LIST OF REFERENCE INDICATORS

1 device

2 rounding tool

3 guide mechanism, linear guide

5 axis

6 axis

7 guide

8 guide

9 moving part, cross slide

10 limit stop

11 limit stop

12 limit stop

13 limit stop

14 receptacle

15 drive

16 drive

17 coupling gear mechanism, traction mechanism, gear mechanism

18 deflecting mechanism

19 deflecting mechanism

20 deflecting mechanism

21 deflecting mechanism

22 deflecting mechanism

23 traction mechanism

24 traction mechanism

25 end

26 end

27 control/regulating device

28 advance unit 

1. A device (1) for rounding ends of filaments for a toothbrush head, having a rounding tool (2) and control equipment (3) for guiding the tool (2) on a movement path that processes the filaments, characterized in that the control equipment is fashioned as a linear guide (3) by means of which the tool (2) is capable of being maneuverable linearly relative to at least two axes (5, 6).
 2. The device according to claim 1, characterized in that the control equipment (3) is formed by at least two guides (7, 8), and one of the guides (7, 8) is preferably allocated respectively to each of the at least two axes (5, 6).
 3. The device according to claim 2, characterized in that the guides (7, 8) are movable relative to one another.
 4. The device according to claim 2 or 3, characterized in that at least one of the guides (7, 8) is situated so as to be stationary, and the other guide (8) is capable of being maneuverable relative thereto.
 5. The device according to any one of claims 2 through 4, characterized in that if a movable guide (8) is present, the tool (2) or a receptacle (14) for the tool (2) can be fixed to said guide.
 6. The device according to any one of claims 2 through 5, characterized in that the guides (7, 8) can be oriented to one another in such a way that the axes (5, 6) lie at a specified angle to one another.
 7. The device according to any one of claims 2 through 6, characterized in that the guides (7, 8) are situated relative to one another in such a way that the axes (5, 6) are at a right angle to one another.
 8. The device according to any one of claims 2 through 7, characterized in that the guides (7, 8) are coupled to one another via a moving part (9) that is preferably mounted on one of the guides (7, 8) so as to be capable of being displaced, and on which the other guide (8) is mounted so as to be capable of being maneuvered.
 9. The device according to claim 8, characterized in that the moving part is fashioned as a cross slide (9) or as a pivot slide.
 10. The device according to any one of claims 2 through 9, characterized in that the guides (7, 8) have lateral limit stops (10, 11, 12, 13).
 11. The device according to any one of the preceding claims, characterized in that at least two drives (15, 16) are provided for the linear operation of the tool (2).
 12. The device according to claim 11, characterized in that the drives are fashioned as rotary drives (15, 16) that are effectively connected to the tool (2) via a coupling gear mechanism (17).
 13. The device according to claim 12, characterized in that the rotational speed of the drives (15, 16) can be regulated, and/or the rotational direction of the drives can be reversed.
 14. The device according to claim 12 or 13, characterized in that the drives (15, 16) are effectively connected to one another via the coupling gear mechanism (17) in such a way that when the drives (15, 16) have the same rotational direction, the tool (2) is displaced relative to one of the axes (5, 6), and when the directions of rotation are opposite, the tool is displaced relative to the other axis (6, 5).
 15. The device according to any one of claims 12 through 14, characterized in that the coupling gear mechanism is fashioned as a traction mechanism (17), preferably a belt mechanism.
 16. The device according to claim 15, characterized in that deflecting mechanisms (18, 19, 20, 21, 22) of the traction gear mechanism (17) are situated on the guides (7, 8) and on the moving part (9), via which deflecting mechanism the traction mechanism (23; 24) is deflected, preferably under pretensioning.
 17. The device according to claim 16, characterized in that the deflecting mechanisms (18, 19, 20, 21, 22) are situated with axes parallel to one another, and the traction mechanism (23; 24) is preferably guided in one plane by the deflecting mechanisms (18, 19, 20, 21, 22).
 18. The device according to claim 16 or 17, characterized in that the deflecting mechanisms (18, 19, 20, 21) attached to the guides (7, 8) are situated on the opposite ends of the guides (7, 8), preferably on the lateral limit stops (10, 11, 12, 13) of the guides (7, 8).
 19. The device according to any one of claims 16 through 18, characterized in that the deflecting mechanisms (18, 19) attached to the stationary guide (7) are respectively capable of being driven by one of the drives (15, 16).
 20. The device according to any one of claims 15 through 19, characterized in that the traction mechanism (24) has two ends (25, 26), and a deflecting mechanism (21) attached to the movable guide (8) is fashioned for fixing the ends (25, 26).
 21. The device according to claim 20, characterized in that the ends (25, 26) of the traction mechanism (24) are capable of being fixed to one of the lateral limit stops (12, 13) of the movable guide (8), preferably to the limit stop (13) connected to the tool (2).
 22. The device according to any one of claims 15 through 19, characterized in that the traction mechanism (23) is variable.
 23. The device according to any of the preceding claims, characterized in that at least one device (27) is provided for controlling and/or regulating at least the rotational direction and, if warranted, the rotational speed of the drives (15, 16) as a function of specifiable parameters, in order to describe a specified movement path of the tool (2).
 24. The device according to claim 23, characterized in that the control/regulation device (27) controls or regulates the rotational direction and, if warranted, the rotational speed of the drives (8, 9) in such a way that the movement path of the tool (2) describes a circular, elliptical, figure-eight, or cardioid path, or a simple back-and-forth movement, or also a movement at an angle to each other [sic].
 25. The device according to one of the preceding claims, characterized in that for the processing of the filaments, the tool (2) is fashioned so as to execute a principal movement, such as a rotational movement.
 26. The device according to claim 25, characterized in that the rotational speed and rotational direction of the tool (2) can be controlled.
 27. The device according to any one of the preceding claims, characterized in that an advance unit (28) is provided by means of which the tool (2) can be moved into the processing position and the process parameters are manipulable.
 28. A toothbrush manufacturing machine having a device according to any of the preceding claims. 